Muon accelerators -- Muon lifetime measurements as window to Planck scale physics

Abstract

A prominent effective description of particles interacting with the quantum properties of gravity is through modifications of the general relativistic dispersion relation. Such modified dispersion relations lead to modifications in the relativistic time dilation. A perfect probe for this effect, which goes with the particle energy cubed $E^3$ over the quantum gravity scale $E_{\text{QG}}$ and the square of the particle mass $M^2$ would be a very light unstable particle for which one can detect the lifetime in the laboratory as a function of its energy to very high precision. In this article we conjecture that a muon collider or accelerator would be a perfect tool to investigate the existence of an anomalous time dilation, and with it the fundamental structure of spacetime at the Planck scale.